CD4 Monoclonal FITC Antibody (Clone RIV7)

CD4 is a type I transmembrane glycoprotein that functions as a T cell receptor (TCR) co-receptor.{59673} It exists as a single polypeptide chain composed of four extracellular immunoglobulin-like (Ig-like) domains that interact with MHC class II molecules, a transmembrane domain, and a cytoplasmic tail that associates with the tyrosine kinase LCK and mediates signal transduction to the TCR, which is essential for T cell activation.{59674} It is expressed on the surface of, and used as a marker for, T cells, and its expression is used to characterize the development stage of thymocytes. Upon binding to antigen-displaying MHC class II molecules expressed by antigen-presenting cells (APCs), naïve CD4+ T cells differentiate and proliferate in a cytokine-dependent manner into a variety of T helper (Th) cell subsets, including Th1, Th2, and Th17 cells, which enhance and direct innate and adaptive immune cell responses to numerous pathogens and have additional roles in cancer, asthma and allergy, and autoimmunity.{59675,59676} CD4 is also the receptor for HIV attachment and entry into cells, resulting in depletion of CD4+ cells in patients infected with HIV.{59677,59678} Cayman's CD4 Monoclonal FITC Antibody (Clone RIV7) is composed of an anti-CD4 monoclonal antibody conjugated to fluorescein isothiocyanate (FITC; Item No. 33264) and can be used for flow cytometry (FC).